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<h1 class="settitle" align="center">GNU Compiler Collection (GCC) Internals</h1>
















<p>This file documents the internals of the GNU compilers.
</p><br>
<p>Copyright &copy; 1988-2023 Free Software Foundation, Inc.
</p>
<p>Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.3 or
any later version published by the Free Software Foundation; with the
Invariant Sections being &ldquo;Funding Free Software&rdquo;, the Front-Cover
Texts being (a) (see below), and with the Back-Cover Texts being (b)
(see below).  A copy of the license is included in the section entitled
&ldquo;GNU Free Documentation License&rdquo;.
</p>
<p>(a) The FSF&rsquo;s Front-Cover Text is:
</p>
<p>A GNU Manual
</p>
<p>(b) The FSF&rsquo;s Back-Cover Text is:
</p>
<p>You have freedom to copy and modify this GNU Manual, like GNU
     software.  Copies published by the Free Software Foundation raise
     funds for GNU development.
</p>
<br>

<a name="SEC_Overview"></a>
<h2 class="shortcontents-heading">Short Table of Contents</h2>

<div class="shortcontents">
<ul class="no-bullet">
<li><a name="stoc-Contributing-to-GCC-Development" href="#toc-Contributing-to-GCC-Development">1 Contributing to GCC Development</a></li>
<li><a name="stoc-GCC-and-Portability" href="#toc-GCC-and-Portability">2 GCC and Portability</a></li>
<li><a name="stoc-Interfacing-to-GCC-Output" href="#toc-Interfacing-to-GCC-Output">3 Interfacing to GCC Output</a></li>
<li><a name="stoc-The-GCC-low_002dlevel-runtime-library" href="#toc-The-GCC-low_002dlevel-runtime-library">4 The GCC low-level runtime library</a></li>
<li><a name="stoc-Language-Front-Ends-in-GCC" href="#toc-Language-Front-Ends-in-GCC">5 Language Front Ends in GCC</a></li>
<li><a name="stoc-Source-Tree-Structure-and-Build-System" href="#toc-Source-Tree-Structure-and-Build-System">6 Source Tree Structure and Build System</a></li>
<li><a name="stoc-Testsuites-1" href="#toc-Testsuites-1">7 Testsuites</a></li>
<li><a name="stoc-Option-specification-files" href="#toc-Option-specification-files">8 Option specification files</a></li>
<li><a name="stoc-Passes-and-Files-of-the-Compiler" href="#toc-Passes-and-Files-of-the-Compiler">9 Passes and Files of the Compiler</a></li>
<li><a name="stoc-Sizes-and-offsets-as-runtime-invariants" href="#toc-Sizes-and-offsets-as-runtime-invariants">10 Sizes and offsets as runtime invariants</a></li>
<li><a name="stoc-GENERIC-1" href="#toc-GENERIC-1">11 GENERIC</a></li>
<li><a name="stoc-GIMPLE-1" href="#toc-GIMPLE-1">12 GIMPLE</a></li>
<li><a name="stoc-Analysis-and-Optimization-of-GIMPLE-tuples" href="#toc-Analysis-and-Optimization-of-GIMPLE-tuples">13 Analysis and Optimization of GIMPLE tuples</a></li>
<li><a name="stoc-RTL-Representation" href="#toc-RTL-Representation">14 RTL Representation</a></li>
<li><a name="stoc-Control-Flow-Graph" href="#toc-Control-Flow-Graph">15 Control Flow Graph</a></li>
<li><a name="stoc-Analysis-and-Representation-of-Loops" href="#toc-Analysis-and-Representation-of-Loops">16 Analysis and Representation of Loops</a></li>
<li><a name="stoc-Machine-Descriptions" href="#toc-Machine-Descriptions">17 Machine Descriptions</a></li>
<li><a name="stoc-Target-Description-Macros-and-Functions" href="#toc-Target-Description-Macros-and-Functions">18 Target Description Macros and Functions</a></li>
<li><a name="stoc-Host-Configuration" href="#toc-Host-Configuration">19 Host Configuration</a></li>
<li><a name="stoc-Makefile-Fragments" href="#toc-Makefile-Fragments">20 Makefile Fragments</a></li>
<li><a name="stoc-collect2" href="#toc-collect2">21 <code>collect2</code></a></li>
<li><a name="stoc-Standard-Header-File-Directories" href="#toc-Standard-Header-File-Directories">22 Standard Header File Directories</a></li>
<li><a name="stoc-Memory-Management-and-Type-Information" href="#toc-Memory-Management-and-Type-Information">23 Memory Management and Type Information</a></li>
<li><a name="stoc-Plugins-1" href="#toc-Plugins-1">24 Plugins</a></li>
<li><a name="stoc-Link-Time-Optimization" href="#toc-Link-Time-Optimization">25 Link Time Optimization</a></li>
<li><a name="stoc-Match-and-Simplify-1" href="#toc-Match-and-Simplify-1">26 Match and Simplify</a></li>
<li><a name="stoc-Static-Analyzer-1" href="#toc-Static-Analyzer-1">27 Static Analyzer</a></li>
<li><a name="stoc-User-Experience-Guidelines-1" href="#toc-User-Experience-Guidelines-1">28 User Experience Guidelines</a></li>
<li><a name="stoc-Funding-Free-Software" href="#toc-Funding-Free-Software">Funding Free Software</a></li>
<li><a name="stoc-The-GNU-Project-and-GNU_002fLinux" href="#toc-The-GNU-Project-and-GNU_002fLinux">The GNU Project and GNU/Linux</a></li>
<li><a name="stoc-GNU-General-Public-License" href="#toc-GNU-General-Public-License">GNU General Public License</a></li>
<li><a name="stoc-GNU-Free-Documentation-License-1" href="#toc-GNU-Free-Documentation-License-1">GNU Free Documentation License</a></li>
<li><a name="stoc-Contributors-to-GCC" href="#toc-Contributors-to-GCC">Contributors to GCC</a></li>
<li><a name="stoc-Option-Index-1" href="#toc-Option-Index-1">Option Index</a></li>
<li><a name="stoc-Concept-Index-1" href="#toc-Concept-Index-1">Concept Index</a></li>
</ul>
</div>

<a name="SEC_Contents"></a>
<h2 class="contents-heading">Table of Contents</h2>

<div class="contents">

<ul class="no-bullet">
  <li><a name="toc-Contributing-to-GCC-Development" href="Contributing.html#Contributing">1 Contributing to GCC Development</a></li>
  <li><a name="toc-GCC-and-Portability" href="Portability.html#Portability">2 GCC and Portability</a></li>
  <li><a name="toc-Interfacing-to-GCC-Output" href="Interface.html#Interface">3 Interfacing to GCC Output</a></li>
  <li><a name="toc-The-GCC-low_002dlevel-runtime-library" href="Libgcc.html#Libgcc">4 The GCC low-level runtime library</a>
  <ul class="no-bullet">
    <li><a name="toc-Routines-for-integer-arithmetic" href="Integer-library-routines.html#Integer-library-routines">4.1 Routines for integer arithmetic</a>
    <ul class="no-bullet">
      <li><a name="toc-Arithmetic-functions" href="Integer-library-routines.html#Arithmetic-functions">4.1.1 Arithmetic functions</a></li>
      <li><a name="toc-Comparison-functions" href="Integer-library-routines.html#Comparison-functions">4.1.2 Comparison functions</a></li>
      <li><a name="toc-Trapping-arithmetic-functions" href="Integer-library-routines.html#Trapping-arithmetic-functions">4.1.3 Trapping arithmetic functions</a></li>
      <li><a name="toc-Bit-operations" href="Integer-library-routines.html#Bit-operations">4.1.4 Bit operations</a></li>
    </ul></li>
    <li><a name="toc-Routines-for-floating-point-emulation" href="Soft-float-library-routines.html#Soft-float-library-routines">4.2 Routines for floating point emulation</a>
    <ul class="no-bullet">
      <li><a name="toc-Arithmetic-functions-1" href="Soft-float-library-routines.html#Arithmetic-functions-1">4.2.1 Arithmetic functions</a></li>
      <li><a name="toc-Conversion-functions" href="Soft-float-library-routines.html#Conversion-functions">4.2.2 Conversion functions</a></li>
      <li><a name="toc-Comparison-functions-1" href="Soft-float-library-routines.html#Comparison-functions-1">4.2.3 Comparison functions</a></li>
      <li><a name="toc-Other-floating_002dpoint-functions" href="Soft-float-library-routines.html#Other-floating_002dpoint-functions">4.2.4 Other floating-point functions</a></li>
    </ul></li>
    <li><a name="toc-Routines-for-decimal-floating-point-emulation" href="Decimal-float-library-routines.html#Decimal-float-library-routines">4.3 Routines for decimal floating point emulation</a>
    <ul class="no-bullet">
      <li><a name="toc-Arithmetic-functions-2" href="Decimal-float-library-routines.html#Arithmetic-functions-2">4.3.1 Arithmetic functions</a></li>
      <li><a name="toc-Conversion-functions-1" href="Decimal-float-library-routines.html#Conversion-functions-1">4.3.2 Conversion functions</a></li>
      <li><a name="toc-Comparison-functions-2" href="Decimal-float-library-routines.html#Comparison-functions-2">4.3.3 Comparison functions</a></li>
    </ul></li>
    <li><a name="toc-Routines-for-fixed_002dpoint-fractional-emulation" href="Fixed_002dpoint-fractional-library-routines.html#Fixed_002dpoint-fractional-library-routines">4.4 Routines for fixed-point fractional emulation</a>
    <ul class="no-bullet">
      <li><a name="toc-Arithmetic-functions-3" href="Fixed_002dpoint-fractional-library-routines.html#Arithmetic-functions-3">4.4.1 Arithmetic functions</a></li>
      <li><a name="toc-Comparison-functions-3" href="Fixed_002dpoint-fractional-library-routines.html#Comparison-functions-3">4.4.2 Comparison functions</a></li>
      <li><a name="toc-Conversion-functions-2" href="Fixed_002dpoint-fractional-library-routines.html#Conversion-functions-2">4.4.3 Conversion functions</a></li>
    </ul></li>
    <li><a name="toc-Language_002dindependent-routines-for-exception-handling" href="Exception-handling-routines.html#Exception-handling-routines">4.5 Language-independent routines for exception handling</a></li>
    <li><a name="toc-Miscellaneous-runtime-library-routines" href="Miscellaneous-routines.html#Miscellaneous-routines">4.6 Miscellaneous runtime library routines</a>
    <ul class="no-bullet">
      <li><a name="toc-Cache-control-functions" href="Miscellaneous-routines.html#Cache-control-functions">4.6.1 Cache control functions</a></li>
      <li><a name="toc-Split-stack-functions-and-variables" href="Miscellaneous-routines.html#Split-stack-functions-and-variables">4.6.2 Split stack functions and variables</a></li>
    </ul></li>
  </ul></li>
  <li><a name="toc-Language-Front-Ends-in-GCC" href="Languages.html#Languages">5 Language Front Ends in GCC</a></li>
  <li><a name="toc-Source-Tree-Structure-and-Build-System" href="Source-Tree.html#Source-Tree">6 Source Tree Structure and Build System</a>
  <ul class="no-bullet">
    <li><a name="toc-Configure-Terms-and-History" href="Configure-Terms.html#Configure-Terms">6.1 Configure Terms and History</a></li>
    <li><a name="toc-Top-Level-Source-Directory" href="Top-Level.html#Top-Level">6.2 Top Level Source Directory</a></li>
    <li><a name="toc-The-gcc-Subdirectory" href="gcc-Directory.html#gcc-Directory">6.3 The <samp>gcc</samp> Subdirectory</a>
    <ul class="no-bullet">
      <li><a name="toc-Subdirectories-of-gcc" href="Subdirectories.html#Subdirectories">6.3.1 Subdirectories of <samp>gcc</samp></a></li>
      <li><a name="toc-Configuration-in-the-gcc-Directory" href="Configuration.html#Configuration">6.3.2 Configuration in the <samp>gcc</samp> Directory</a>
      <ul class="no-bullet">
        <li><a name="toc-Scripts-Used-by-configure" href="Config-Fragments.html#Config-Fragments">6.3.2.1 Scripts Used by <samp>configure</samp></a></li>
        <li><a name="toc-The-config_002ebuild_003b-config_002ehost_003b-and-config_002egcc-Files" href="System-Config.html#System-Config">6.3.2.2 The <samp>config.build</samp>; <samp>config.host</samp>; and <samp>config.gcc</samp> Files</a></li>
        <li><a name="toc-Files-Created-by-configure" href="Configuration-Files.html#Configuration-Files">6.3.2.3 Files Created by <code>configure</code></a></li>
      </ul></li>
      <li><a name="toc-Build-System-in-the-gcc-Directory" href="Build.html#Build">6.3.3 Build System in the <samp>gcc</samp> Directory</a></li>
      <li><a name="toc-Makefile-Targets" href="Makefile.html#Makefile">6.3.4 Makefile Targets</a></li>
      <li><a name="toc-Library-Source-Files-and-Headers-under-the-gcc-Directory" href="Library-Files.html#Library-Files">6.3.5 Library Source Files and Headers under the <samp>gcc</samp> Directory</a></li>
      <li><a name="toc-Headers-Installed-by-GCC" href="Headers.html#Headers">6.3.6 Headers Installed by GCC</a></li>
      <li><a name="toc-Building-Documentation" href="Documentation.html#Documentation">6.3.7 Building Documentation</a>
      <ul class="no-bullet">
        <li><a name="toc-Texinfo-Manuals-1" href="Texinfo-Manuals.html#Texinfo-Manuals">6.3.7.1 Texinfo Manuals</a></li>
        <li><a name="toc-Man-Page-Generation-1" href="Man-Page-Generation.html#Man-Page-Generation">6.3.7.2 Man Page Generation</a></li>
        <li><a name="toc-Miscellaneous-Documentation" href="Miscellaneous-Docs.html#Miscellaneous-Docs">6.3.7.3 Miscellaneous Documentation</a></li>
      </ul></li>
      <li><a name="toc-Anatomy-of-a-Language-Front-End" href="Front-End.html#Front-End">6.3.8 Anatomy of a Language Front End</a>
      <ul class="no-bullet">
        <li><a name="toc-The-Front-End-language-Directory" href="Front-End-Directory.html#Front-End-Directory">6.3.8.1 The Front End <samp><var>language</var></samp> Directory</a></li>
        <li><a name="toc-The-Front-End-config_002dlang_002ein-File" href="Front-End-Config.html#Front-End-Config">6.3.8.2 The Front End <samp>config-lang.in</samp> File</a></li>
        <li><a name="toc-The-Front-End-Make_002dlang_002ein-File" href="Front-End-Makefile.html#Front-End-Makefile">6.3.8.3 The Front End <samp>Make-lang.in</samp> File</a></li>
      </ul></li>
      <li><a name="toc-Anatomy-of-a-Target-Back-End" href="Back-End.html#Back-End">6.3.9 Anatomy of a Target Back End</a></li>
    </ul></li>
  </ul></li>
  <li><a name="toc-Testsuites-1" href="Testsuites.html#Testsuites">7 Testsuites</a>
  <ul class="no-bullet">
    <li><a name="toc-Idioms-Used-in-Testsuite-Code" href="Test-Idioms.html#Test-Idioms">7.1 Idioms Used in Testsuite Code</a></li>
    <li><a name="toc-Directives-used-within-DejaGnu-tests" href="Test-Directives.html#Test-Directives">7.2 Directives used within DejaGnu tests</a>
    <ul class="no-bullet">
      <li><a name="toc-Syntax-and-Descriptions-of-test-directives" href="Directives.html#Directives">7.2.1 Syntax and Descriptions of test directives</a>
      <ul class="no-bullet">
        <li><a name="toc-Specify-how-to-build-the-test" href="Directives.html#Specify-how-to-build-the-test">7.2.1.1 Specify how to build the test</a></li>
        <li><a name="toc-Specify-additional-compiler-options" href="Directives.html#Specify-additional-compiler-options">7.2.1.2 Specify additional compiler options</a></li>
        <li><a name="toc-Modify-the-test-timeout-value" href="Directives.html#Modify-the-test-timeout-value">7.2.1.3 Modify the test timeout value</a></li>
        <li><a name="toc-Skip-a-test-for-some-targets" href="Directives.html#Skip-a-test-for-some-targets">7.2.1.4 Skip a test for some targets</a></li>
        <li><a name="toc-Expect-a-test-to-fail-for-some-targets" href="Directives.html#Expect-a-test-to-fail-for-some-targets">7.2.1.5 Expect a test to fail for some targets</a></li>
        <li><a name="toc-Expect-the-compiler-to-crash" href="Directives.html#Expect-the-compiler-to-crash">7.2.1.6 Expect the compiler to crash</a></li>
        <li><a name="toc-Expect-the-test-executable-to-fail" href="Directives.html#Expect-the-test-executable-to-fail">7.2.1.7 Expect the test executable to fail</a></li>
        <li><a name="toc-Verify-compiler-messages" href="Directives.html#Verify-compiler-messages">7.2.1.8 Verify compiler messages</a></li>
        <li><a name="toc-Verify-output-of-the-test-executable" href="Directives.html#Verify-output-of-the-test-executable">7.2.1.9 Verify output of the test executable</a></li>
        <li><a name="toc-Specify-environment-variables-for-a-test" href="Directives.html#Specify-environment-variables-for-a-test">7.2.1.10 Specify environment variables for a test</a></li>
        <li><a name="toc-Specify-additional-files-for-a-test" href="Directives.html#Specify-additional-files-for-a-test">7.2.1.11 Specify additional files for a test</a></li>
        <li><a name="toc-Add-checks-at-the-end-of-a-test" href="Directives.html#Add-checks-at-the-end-of-a-test">7.2.1.12 Add checks at the end of a test</a></li>
      </ul></li>
      <li><a name="toc-Selecting-targets-to-which-a-test-applies" href="Selectors.html#Selectors">7.2.2 Selecting targets to which a test applies</a></li>
      <li><a name="toc-Keywords-describing-target-attributes" href="Effective_002dTarget-Keywords.html#Effective_002dTarget-Keywords">7.2.3 Keywords describing target attributes</a>
      <ul class="no-bullet">
        <li><a name="toc-Endianness" href="Effective_002dTarget-Keywords.html#Endianness">7.2.3.1 Endianness</a></li>
        <li><a name="toc-Data-type-sizes" href="Effective_002dTarget-Keywords.html#Data-type-sizes">7.2.3.2 Data type sizes</a></li>
        <li><a name="toc-Fortran_002dspecific-attributes" href="Effective_002dTarget-Keywords.html#Fortran_002dspecific-attributes">7.2.3.3 Fortran-specific attributes</a></li>
        <li><a name="toc-Vector_002dspecific-attributes" href="Effective_002dTarget-Keywords.html#Vector_002dspecific-attributes">7.2.3.4 Vector-specific attributes</a></li>
        <li><a name="toc-Thread-Local-Storage-attributes" href="Effective_002dTarget-Keywords.html#Thread-Local-Storage-attributes">7.2.3.5 Thread Local Storage attributes</a></li>
        <li><a name="toc-Decimal-floating-point-attributes" href="Effective_002dTarget-Keywords.html#Decimal-floating-point-attributes">7.2.3.6 Decimal floating point attributes</a></li>
        <li><a name="toc-ARM_002dspecific-attributes" href="Effective_002dTarget-Keywords.html#ARM_002dspecific-attributes">7.2.3.7 ARM-specific attributes</a></li>
        <li><a name="toc-AArch64_002dspecific-attributes" href="Effective_002dTarget-Keywords.html#AArch64_002dspecific-attributes">7.2.3.8 AArch64-specific attributes</a></li>
        <li><a name="toc-MIPS_002dspecific-attributes" href="Effective_002dTarget-Keywords.html#MIPS_002dspecific-attributes">7.2.3.9 MIPS-specific attributes</a></li>
        <li><a name="toc-MSP430_002dspecific-attributes" href="Effective_002dTarget-Keywords.html#MSP430_002dspecific-attributes">7.2.3.10 MSP430-specific attributes</a></li>
        <li><a name="toc-PowerPC_002dspecific-attributes" href="Effective_002dTarget-Keywords.html#PowerPC_002dspecific-attributes">7.2.3.11 PowerPC-specific attributes</a></li>
        <li><a name="toc-RISC_002dV-specific-attributes" href="Effective_002dTarget-Keywords.html#RISC_002dV-specific-attributes">7.2.3.12 RISC-V specific attributes</a></li>
        <li><a name="toc-Other-hardware-attributes" href="Effective_002dTarget-Keywords.html#Other-hardware-attributes">7.2.3.13 Other hardware attributes</a></li>
        <li><a name="toc-Environment-attributes" href="Effective_002dTarget-Keywords.html#Environment-attributes">7.2.3.14 Environment attributes</a></li>
        <li><a name="toc-Other-attributes" href="Effective_002dTarget-Keywords.html#Other-attributes">7.2.3.15 Other attributes</a></li>
        <li><a name="toc-Local-to-tests-in-gcc_002etarget_002fi386" href="Effective_002dTarget-Keywords.html#Local-to-tests-in-gcc_002etarget_002fi386">7.2.3.16 Local to tests in <code>gcc.target/i386</code></a></li>
        <li><a name="toc-Local-to-tests-in-gcc_002etest_002dframework" href="Effective_002dTarget-Keywords.html#Local-to-tests-in-gcc_002etest_002dframework">7.2.3.17 Local to tests in <code>gcc.test-framework</code></a></li>
      </ul></li>
      <li><a name="toc-Features-for-dg_002dadd_002doptions" href="Add-Options.html#Add-Options">7.2.4 Features for <code>dg-add-options</code></a></li>
      <li><a name="toc-Variants-of-dg_002drequire_002dsupport" href="Require-Support.html#Require-Support">7.2.5 Variants of <code>dg-require-<var>support</var></code></a></li>
      <li><a name="toc-Commands-for-use-in-dg_002dfinal" href="Final-Actions.html#Final-Actions">7.2.6 Commands for use in <code>dg-final</code></a>
      <ul class="no-bullet">
        <li><a name="toc-Scan-a-particular-file" href="Final-Actions.html#Scan-a-particular-file">7.2.6.1 Scan a particular file</a></li>
        <li><a name="toc-Scan-the-assembly-output" href="Final-Actions.html#Scan-the-assembly-output">7.2.6.2 Scan the assembly output</a></li>
        <li><a name="toc-Scan-optimization-dump-files" href="Final-Actions.html#Scan-optimization-dump-files">7.2.6.3 Scan optimization dump files</a></li>
        <li><a name="toc-Check-for-output-files" href="Final-Actions.html#Check-for-output-files">7.2.6.4 Check for output files</a></li>
        <li><a name="toc-Checks-for-gcov-tests" href="Final-Actions.html#Checks-for-gcov-tests">7.2.6.5 Checks for <code>gcov</code> tests</a></li>
        <li><a name="toc-Clean-up-generated-test-files" href="Final-Actions.html#Clean-up-generated-test-files">7.2.6.6 Clean up generated test files</a></li>
      </ul></li>
    </ul></li>
    <li><a name="toc-Ada-Language-Testsuites" href="Ada-Tests.html#Ada-Tests">7.3 Ada Language Testsuites</a></li>
    <li><a name="toc-C-Language-Testsuites" href="C-Tests.html#C-Tests">7.4 C Language Testsuites</a></li>
    <li><a name="toc-Support-for-testing-link_002dtime-optimizations" href="LTO-Testing.html#LTO-Testing">7.5 Support for testing link-time optimizations</a></li>
    <li><a name="toc-Support-for-testing-gcov" href="gcov-Testing.html#gcov-Testing">7.6 Support for testing <code>gcov</code></a></li>
    <li><a name="toc-Support-for-testing-profile_002ddirected-optimizations" href="profopt-Testing.html#profopt-Testing">7.7 Support for testing profile-directed optimizations</a></li>
    <li><a name="toc-Support-for-testing-binary-compatibility" href="compat-Testing.html#compat-Testing">7.8 Support for testing binary compatibility</a></li>
    <li><a name="toc-Support-for-torture-testing-using-multiple-options" href="Torture-Tests.html#Torture-Tests">7.9 Support for torture testing using multiple options</a></li>
    <li><a name="toc-Support-for-testing-GIMPLE-passes" href="GIMPLE-Tests.html#GIMPLE-Tests">7.10 Support for testing GIMPLE passes</a></li>
    <li><a name="toc-Support-for-testing-RTL-passes" href="RTL-Tests.html#RTL-Tests">7.11 Support for testing RTL passes</a></li>
  </ul></li>
  <li><a name="toc-Option-specification-files" href="Options.html#Options">8 Option specification files</a>
  <ul class="no-bullet">
    <li><a name="toc-Option-file-format-1" href="Option-file-format.html#Option-file-format">8.1 Option file format</a></li>
    <li><a name="toc-Option-properties-1" href="Option-properties.html#Option-properties">8.2 Option properties</a></li>
  </ul></li>
  <li><a name="toc-Passes-and-Files-of-the-Compiler" href="Passes.html#Passes">9 Passes and Files of the Compiler</a>
  <ul class="no-bullet">
    <li><a name="toc-Parsing-pass-1" href="Parsing-pass.html#Parsing-pass">9.1 Parsing pass</a></li>
    <li><a name="toc-Gimplification-pass-1" href="Gimplification-pass.html#Gimplification-pass">9.2 Gimplification pass</a></li>
    <li><a name="toc-Pass-manager-1" href="Pass-manager.html#Pass-manager">9.3 Pass manager</a></li>
    <li><a name="toc-Inter_002dprocedural-optimization-passes" href="IPA-passes.html#IPA-passes">9.4 Inter-procedural optimization passes</a>
    <ul class="no-bullet">
      <li><a name="toc-Small-IPA-passes-1" href="Small-IPA-passes.html#Small-IPA-passes">9.4.1 Small IPA passes</a></li>
      <li><a name="toc-Regular-IPA-passes-1" href="Regular-IPA-passes.html#Regular-IPA-passes">9.4.2 Regular IPA passes</a></li>
      <li><a name="toc-Late-IPA-passes-1" href="Late-IPA-passes.html#Late-IPA-passes">9.4.3 Late IPA passes</a></li>
    </ul></li>
    <li><a name="toc-Tree-SSA-passes-1" href="Tree-SSA-passes.html#Tree-SSA-passes">9.5 Tree SSA passes</a></li>
    <li><a name="toc-RTL-passes-1" href="RTL-passes.html#RTL-passes">9.6 RTL passes</a></li>
    <li><a name="toc-Optimization-info-1" href="Optimization-info.html#Optimization-info">9.7 Optimization info</a>
    <ul class="no-bullet">
      <li><a name="toc-Dump-setup-1" href="Dump-setup.html#Dump-setup">9.7.1 Dump setup</a></li>
      <li><a name="toc-Optimization-groups-1" href="Optimization-groups.html#Optimization-groups">9.7.2 Optimization groups</a></li>
      <li><a name="toc-Dump-files-and-streams-1" href="Dump-files-and-streams.html#Dump-files-and-streams">9.7.3 Dump files and streams</a></li>
      <li><a name="toc-Dump-output-verbosity-1" href="Dump-output-verbosity.html#Dump-output-verbosity">9.7.4 Dump output verbosity</a></li>
      <li><a name="toc-Dump-types-1" href="Dump-types.html#Dump-types">9.7.5 Dump types</a></li>
      <li><a name="toc-Dump-examples-1" href="Dump-examples.html#Dump-examples">9.7.6 Dump examples</a></li>
    </ul></li>
  </ul></li>
  <li><a name="toc-Sizes-and-offsets-as-runtime-invariants" href="poly_005fint.html#poly_005fint">10 Sizes and offsets as runtime invariants</a>
  <ul class="no-bullet">
    <li><a name="toc-Overview-of-poly_005fint-1" href="Overview-of-poly_005fint.html#Overview-of-poly_005fint">10.1 Overview of <code>poly_int</code></a></li>
    <li><a name="toc-Consequences-of-using-poly_005fint-1" href="Consequences-of-using-poly_005fint.html#Consequences-of-using-poly_005fint">10.2 Consequences of using <code>poly_int</code></a></li>
    <li><a name="toc-Comparisons-involving-poly_005fint-1" href="Comparisons-involving-poly_005fint.html#Comparisons-involving-poly_005fint">10.3 Comparisons involving <code>poly_int</code></a>
    <ul class="no-bullet">
      <li><a name="toc-Comparison-functions-for-poly_005fint-1" href="Comparison-functions-for-poly_005fint.html#Comparison-functions-for-poly_005fint">10.3.1 Comparison functions for <code>poly_int</code></a></li>
      <li><a name="toc-Properties-of-the-poly_005fint-comparisons-1" href="Properties-of-the-poly_005fint-comparisons.html#Properties-of-the-poly_005fint-comparisons">10.3.2 Properties of the <code>poly_int</code> comparisons</a></li>
      <li><a name="toc-Comparing-potentially_002dunordered-poly_005fints-1" href="Comparing-potentially_002dunordered-poly_005fints.html#Comparing-potentially_002dunordered-poly_005fints">10.3.3 Comparing potentially-unordered <code>poly_int</code>s</a></li>
      <li><a name="toc-Comparing-ordered-poly_005fints-1" href="Comparing-ordered-poly_005fints.html#Comparing-ordered-poly_005fints">10.3.4 Comparing ordered <code>poly_int</code>s</a></li>
      <li><a name="toc-Checking-for-a-poly_005fint-marker-value-1" href="Checking-for-a-poly_005fint-marker-value.html#Checking-for-a-poly_005fint-marker-value">10.3.5 Checking for a <code>poly_int</code> marker value</a></li>
      <li><a name="toc-Range-checks-on-poly_005fints-1" href="Range-checks-on-poly_005fints.html#Range-checks-on-poly_005fints">10.3.6 Range checks on <code>poly_int</code>s</a></li>
      <li><a name="toc-Sorting-poly_005fints-1" href="Sorting-poly_005fints.html#Sorting-poly_005fints">10.3.7 Sorting <code>poly_int</code>s</a></li>
    </ul></li>
    <li><a name="toc-Arithmetic-on-poly_005fints-1" href="Arithmetic-on-poly_005fints.html#Arithmetic-on-poly_005fints">10.4 Arithmetic on <code>poly_int</code>s</a>
    <ul class="no-bullet">
      <li><a name="toc-Using-poly_005fint-with-C_002b_002b-arithmetic-operators-1" href="Using-poly_005fint-with-C_002b_002b-arithmetic-operators.html#Using-poly_005fint-with-C_002b_002b-arithmetic-operators">10.4.1 Using <code>poly_int</code> with C++ arithmetic operators</a></li>
      <li><a name="toc-wi-arithmetic-on-poly_005fints-1" href="wi-arithmetic-on-poly_005fints.html#wi-arithmetic-on-poly_005fints">10.4.2 <code>wi</code> arithmetic on <code>poly_int</code>s</a></li>
      <li><a name="toc-Division-of-poly_005fints-1" href="Division-of-poly_005fints.html#Division-of-poly_005fints">10.4.3 Division of <code>poly_int</code>s</a></li>
      <li><a name="toc-Other-poly_005fint-arithmetic-1" href="Other-poly_005fint-arithmetic.html#Other-poly_005fint-arithmetic">10.4.4 Other <code>poly_int</code> arithmetic</a></li>
    </ul></li>
    <li><a name="toc-Alignment-of-poly_005fints-1" href="Alignment-of-poly_005fints.html#Alignment-of-poly_005fints">10.5 Alignment of <code>poly_int</code>s</a></li>
    <li><a name="toc-Computing-bounds-on-poly_005fints-1" href="Computing-bounds-on-poly_005fints.html#Computing-bounds-on-poly_005fints">10.6 Computing bounds on <code>poly_int</code>s</a></li>
    <li><a name="toc-Converting-poly_005fints-1" href="Converting-poly_005fints.html#Converting-poly_005fints">10.7 Converting <code>poly_int</code>s</a></li>
    <li><a name="toc-Miscellaneous-poly_005fint-routines-1" href="Miscellaneous-poly_005fint-routines.html#Miscellaneous-poly_005fint-routines">10.8 Miscellaneous <code>poly_int</code> routines</a></li>
    <li><a name="toc-Guidelines-for-using-poly_005fint-1" href="Guidelines-for-using-poly_005fint.html#Guidelines-for-using-poly_005fint">10.9 Guidelines for using <code>poly_int</code></a></li>
  </ul></li>
  <li><a name="toc-GENERIC-1" href="GENERIC.html#GENERIC">11 GENERIC</a>
  <ul class="no-bullet">
    <li><a name="toc-Deficiencies-1" href="Deficiencies.html#Deficiencies">11.1 Deficiencies</a></li>
    <li><a name="toc-Overview-1" href="Tree-overview.html#Tree-overview">11.2 Overview</a>
    <ul class="no-bullet">
      <li><a name="toc-Trees" href="Macros-and-Functions.html#Macros-and-Functions">11.2.1 Trees</a></li>
      <li><a name="toc-Identifiers-1" href="Identifiers.html#Identifiers">11.2.2 Identifiers</a></li>
      <li><a name="toc-Containers-1" href="Containers.html#Containers">11.2.3 Containers</a></li>
    </ul></li>
    <li><a name="toc-Types-1" href="Types.html#Types">11.3 Types</a></li>
    <li><a name="toc-Declarations-1" href="Declarations.html#Declarations">11.4 Declarations</a>
    <ul class="no-bullet">
      <li><a name="toc-Working-with-declarations-1" href="Working-with-declarations.html#Working-with-declarations">11.4.1 Working with declarations</a></li>
      <li><a name="toc-Internal-structure-1" href="Internal-structure.html#Internal-structure">11.4.2 Internal structure</a>
      <ul class="no-bullet">
        <li><a name="toc-Current-structure-hierarchy-1" href="Current-structure-hierarchy.html#Current-structure-hierarchy">11.4.2.1 Current structure hierarchy</a></li>
        <li><a name="toc-Adding-new-DECL-node-types-1" href="Adding-new-DECL-node-types.html#Adding-new-DECL-node-types">11.4.2.2 Adding new DECL node types</a></li>
      </ul></li>
    </ul></li>
    <li><a name="toc-Attributes-in-trees" href="Attributes.html#Attributes">11.5 Attributes in trees</a></li>
    <li><a name="toc-Expressions-1" href="Expression-trees.html#Expression-trees">11.6 Expressions</a>
    <ul class="no-bullet">
      <li><a name="toc-Constant-expressions-1" href="Constant-expressions.html#Constant-expressions">11.6.1 Constant expressions</a></li>
      <li><a name="toc-References-to-storage" href="Storage-References.html#Storage-References">11.6.2 References to storage</a></li>
      <li><a name="toc-Unary-and-Binary-Expressions-1" href="Unary-and-Binary-Expressions.html#Unary-and-Binary-Expressions">11.6.3 Unary and Binary Expressions</a></li>
      <li><a name="toc-Vectors-1" href="Vectors.html#Vectors">11.6.4 Vectors</a></li>
    </ul></li>
    <li><a name="toc-Statements-1" href="Statements.html#Statements">11.7 Statements</a>
    <ul class="no-bullet">
      <li><a name="toc-Basic-Statements-1" href="Basic-Statements.html#Basic-Statements">11.7.1 Basic Statements</a></li>
      <li><a name="toc-Blocks-1" href="Blocks.html#Blocks">11.7.2 Blocks</a></li>
      <li><a name="toc-Statement-Sequences-1" href="Statement-Sequences.html#Statement-Sequences">11.7.3 Statement Sequences</a></li>
      <li><a name="toc-Empty-Statements-1" href="Empty-Statements.html#Empty-Statements">11.7.4 Empty Statements</a></li>
      <li><a name="toc-Jumps-1" href="Jumps.html#Jumps">11.7.5 Jumps</a></li>
      <li><a name="toc-Cleanups-1" href="Cleanups.html#Cleanups">11.7.6 Cleanups</a></li>
      <li><a name="toc-OpenMP-1" href="OpenMP.html#OpenMP">11.7.7 OpenMP</a></li>
      <li><a name="toc-OpenACC-1" href="OpenACC.html#OpenACC">11.7.8 OpenACC</a></li>
    </ul></li>
    <li><a name="toc-Functions-1" href="Functions.html#Functions">11.8 Functions</a>
    <ul class="no-bullet">
      <li><a name="toc-Function-Basics-1" href="Function-Basics.html#Function-Basics">11.8.1 Function Basics</a></li>
      <li><a name="toc-Function-Properties-1" href="Function-Properties.html#Function-Properties">11.8.2 Function Properties</a></li>
    </ul></li>
    <li><a name="toc-Language_002ddependent-trees-1" href="Language_002ddependent-trees.html#Language_002ddependent-trees">11.9 Language-dependent trees</a></li>
    <li><a name="toc-C-and-C_002b_002b-Trees-1" href="C-and-C_002b_002b-Trees.html#C-and-C_002b_002b-Trees">11.10 C and C++ Trees</a>
    <ul class="no-bullet">
      <li><a name="toc-Types-for-C_002b_002b-1" href="Types-for-C_002b_002b.html#Types-for-C_002b_002b">11.10.1 Types for C++</a></li>
      <li><a name="toc-Namespaces-1" href="Namespaces.html#Namespaces">11.10.2 Namespaces</a></li>
      <li><a name="toc-Classes-1" href="Classes.html#Classes">11.10.3 Classes</a></li>
      <li><a name="toc-Functions-for-C_002b_002b-1" href="Functions-for-C_002b_002b.html#Functions-for-C_002b_002b">11.10.4 Functions for C++</a></li>
      <li><a name="toc-Statements-for-C-and-C_002b_002b-1" href="Statements-for-C-and-C_002b_002b.html#Statements-for-C-and-C_002b_002b">11.10.5 Statements for C and C++</a></li>
      <li><a name="toc-C_002b_002b-Expressions-1" href="C_002b_002b-Expressions.html#C_002b_002b-Expressions">11.10.6 C++ Expressions</a></li>
    </ul></li>
  </ul></li>
  <li><a name="toc-GIMPLE-1" href="GIMPLE.html#GIMPLE">12 GIMPLE</a>
  <ul class="no-bullet">
    <li><a name="toc-Tuple-representation-1" href="Tuple-representation.html#Tuple-representation">12.1 Tuple representation</a>
    <ul class="no-bullet">
      <li><a name="toc-gimple-_0028gsbase_0029" href="Tuple-representation.html#gimple-_0028gsbase_0029">12.1.1 <code>gimple</code> (gsbase)</a></li>
      <li><a name="toc-gimple_005fstatement_005fwith_005fops" href="Tuple-representation.html#gimple_005fstatement_005fwith_005fops">12.1.2 <code>gimple_statement_with_ops</code></a></li>
      <li><a name="toc-gimple_005fstatement_005fwith_005fmemory_005fops" href="Tuple-representation.html#gimple_005fstatement_005fwith_005fmemory_005fops">12.1.3 <code>gimple_statement_with_memory_ops</code></a></li>
    </ul></li>
    <li><a name="toc-Class-hierarchy-of-GIMPLE-statements-1" href="Class-hierarchy-of-GIMPLE-statements.html#Class-hierarchy-of-GIMPLE-statements">12.2 Class hierarchy of GIMPLE statements</a></li>
    <li><a name="toc-GIMPLE-instruction-set-1" href="GIMPLE-instruction-set.html#GIMPLE-instruction-set">12.3 GIMPLE instruction set</a></li>
    <li><a name="toc-Exception-Handling-1" href="GIMPLE-Exception-Handling.html#GIMPLE-Exception-Handling">12.4 Exception Handling</a></li>
    <li><a name="toc-Temporaries-1" href="Temporaries.html#Temporaries">12.5 Temporaries</a></li>
    <li><a name="toc-Operands-1" href="Operands.html#Operands">12.6 Operands</a>
    <ul class="no-bullet">
      <li><a name="toc-Compound-Expressions-1" href="Compound-Expressions.html#Compound-Expressions">12.6.1 Compound Expressions</a></li>
      <li><a name="toc-Compound-Lvalues-1" href="Compound-Lvalues.html#Compound-Lvalues">12.6.2 Compound Lvalues</a></li>
      <li><a name="toc-Conditional-Expressions-1" href="Conditional-Expressions.html#Conditional-Expressions">12.6.3 Conditional Expressions</a></li>
      <li><a name="toc-Logical-Operators-1" href="Logical-Operators.html#Logical-Operators">12.6.4 Logical Operators</a></li>
      <li><a name="toc-Manipulating-operands" href="Logical-Operators.html#Manipulating-operands">12.6.5 Manipulating operands</a></li>
      <li><a name="toc-Operand-vector-allocation" href="Logical-Operators.html#Operand-vector-allocation">12.6.6 Operand vector allocation</a></li>
      <li><a name="toc-Operand-validation" href="Logical-Operators.html#Operand-validation">12.6.7 Operand validation</a></li>
      <li><a name="toc-Statement-validation" href="Logical-Operators.html#Statement-validation">12.6.8 Statement validation</a></li>
    </ul></li>
    <li><a name="toc-Manipulating-GIMPLE-statements-1" href="Manipulating-GIMPLE-statements.html#Manipulating-GIMPLE-statements">12.7 Manipulating GIMPLE statements</a>
    <ul class="no-bullet">
      <li><a name="toc-Common-accessors" href="Manipulating-GIMPLE-statements.html#Common-accessors">12.7.1 Common accessors</a></li>
    </ul></li>
    <li><a name="toc-Tuple-specific-accessors-1" href="Tuple-specific-accessors.html#Tuple-specific-accessors">12.8 Tuple specific accessors</a>
    <ul class="no-bullet">
      <li><a name="toc-GIMPLE_005fASM-1" href="GIMPLE_005fASM.html#GIMPLE_005fASM">12.8.1 <code>GIMPLE_ASM</code></a></li>
      <li><a name="toc-GIMPLE_005fASSIGN-1" href="GIMPLE_005fASSIGN.html#GIMPLE_005fASSIGN">12.8.2 <code>GIMPLE_ASSIGN</code></a></li>
      <li><a name="toc-GIMPLE_005fBIND-1" href="GIMPLE_005fBIND.html#GIMPLE_005fBIND">12.8.3 <code>GIMPLE_BIND</code></a></li>
      <li><a name="toc-GIMPLE_005fCALL-1" href="GIMPLE_005fCALL.html#GIMPLE_005fCALL">12.8.4 <code>GIMPLE_CALL</code></a></li>
      <li><a name="toc-GIMPLE_005fCATCH-1" href="GIMPLE_005fCATCH.html#GIMPLE_005fCATCH">12.8.5 <code>GIMPLE_CATCH</code></a></li>
      <li><a name="toc-GIMPLE_005fCOND-1" href="GIMPLE_005fCOND.html#GIMPLE_005fCOND">12.8.6 <code>GIMPLE_COND</code></a></li>
      <li><a name="toc-GIMPLE_005fDEBUG-1" href="GIMPLE_005fDEBUG.html#GIMPLE_005fDEBUG">12.8.7 <code>GIMPLE_DEBUG</code></a></li>
      <li><a name="toc-GIMPLE_005fEH_005fFILTER-1" href="GIMPLE_005fEH_005fFILTER.html#GIMPLE_005fEH_005fFILTER">12.8.8 <code>GIMPLE_EH_FILTER</code></a></li>
      <li><a name="toc-GIMPLE_005fLABEL-1" href="GIMPLE_005fLABEL.html#GIMPLE_005fLABEL">12.8.9 <code>GIMPLE_LABEL</code></a></li>
      <li><a name="toc-GIMPLE_005fGOTO-1" href="GIMPLE_005fGOTO.html#GIMPLE_005fGOTO">12.8.10 <code>GIMPLE_GOTO</code></a></li>
      <li><a name="toc-GIMPLE_005fNOP-1" href="GIMPLE_005fNOP.html#GIMPLE_005fNOP">12.8.11 <code>GIMPLE_NOP</code></a></li>
      <li><a name="toc-GIMPLE_005fOMP_005fATOMIC_005fLOAD-1" href="GIMPLE_005fOMP_005fATOMIC_005fLOAD.html#GIMPLE_005fOMP_005fATOMIC_005fLOAD">12.8.12 <code>GIMPLE_OMP_ATOMIC_LOAD</code></a></li>
      <li><a name="toc-GIMPLE_005fOMP_005fATOMIC_005fSTORE-1" href="GIMPLE_005fOMP_005fATOMIC_005fSTORE.html#GIMPLE_005fOMP_005fATOMIC_005fSTORE">12.8.13 <code>GIMPLE_OMP_ATOMIC_STORE</code></a></li>
      <li><a name="toc-GIMPLE_005fOMP_005fCONTINUE-1" href="GIMPLE_005fOMP_005fCONTINUE.html#GIMPLE_005fOMP_005fCONTINUE">12.8.14 <code>GIMPLE_OMP_CONTINUE</code></a></li>
      <li><a name="toc-GIMPLE_005fOMP_005fCRITICAL-1" href="GIMPLE_005fOMP_005fCRITICAL.html#GIMPLE_005fOMP_005fCRITICAL">12.8.15 <code>GIMPLE_OMP_CRITICAL</code></a></li>
      <li><a name="toc-GIMPLE_005fOMP_005fFOR-1" href="GIMPLE_005fOMP_005fFOR.html#GIMPLE_005fOMP_005fFOR">12.8.16 <code>GIMPLE_OMP_FOR</code></a></li>
      <li><a name="toc-GIMPLE_005fOMP_005fMASTER-1" href="GIMPLE_005fOMP_005fMASTER.html#GIMPLE_005fOMP_005fMASTER">12.8.17 <code>GIMPLE_OMP_MASTER</code></a></li>
      <li><a name="toc-GIMPLE_005fOMP_005fORDERED-1" href="GIMPLE_005fOMP_005fORDERED.html#GIMPLE_005fOMP_005fORDERED">12.8.18 <code>GIMPLE_OMP_ORDERED</code></a></li>
      <li><a name="toc-GIMPLE_005fOMP_005fPARALLEL-1" href="GIMPLE_005fOMP_005fPARALLEL.html#GIMPLE_005fOMP_005fPARALLEL">12.8.19 <code>GIMPLE_OMP_PARALLEL</code></a></li>
      <li><a name="toc-GIMPLE_005fOMP_005fRETURN-1" href="GIMPLE_005fOMP_005fRETURN.html#GIMPLE_005fOMP_005fRETURN">12.8.20 <code>GIMPLE_OMP_RETURN</code></a></li>
      <li><a name="toc-GIMPLE_005fOMP_005fSECTION-1" href="GIMPLE_005fOMP_005fSECTION.html#GIMPLE_005fOMP_005fSECTION">12.8.21 <code>GIMPLE_OMP_SECTION</code></a></li>
      <li><a name="toc-GIMPLE_005fOMP_005fSECTIONS-1" href="GIMPLE_005fOMP_005fSECTIONS.html#GIMPLE_005fOMP_005fSECTIONS">12.8.22 <code>GIMPLE_OMP_SECTIONS</code></a></li>
      <li><a name="toc-GIMPLE_005fOMP_005fSINGLE-1" href="GIMPLE_005fOMP_005fSINGLE.html#GIMPLE_005fOMP_005fSINGLE">12.8.23 <code>GIMPLE_OMP_SINGLE</code></a></li>
      <li><a name="toc-GIMPLE_005fPHI-1" href="GIMPLE_005fPHI.html#GIMPLE_005fPHI">12.8.24 <code>GIMPLE_PHI</code></a></li>
      <li><a name="toc-GIMPLE_005fRESX-1" href="GIMPLE_005fRESX.html#GIMPLE_005fRESX">12.8.25 <code>GIMPLE_RESX</code></a></li>
      <li><a name="toc-GIMPLE_005fRETURN-1" href="GIMPLE_005fRETURN.html#GIMPLE_005fRETURN">12.8.26 <code>GIMPLE_RETURN</code></a></li>
      <li><a name="toc-GIMPLE_005fSWITCH-1" href="GIMPLE_005fSWITCH.html#GIMPLE_005fSWITCH">12.8.27 <code>GIMPLE_SWITCH</code></a></li>
      <li><a name="toc-GIMPLE_005fTRY-1" href="GIMPLE_005fTRY.html#GIMPLE_005fTRY">12.8.28 <code>GIMPLE_TRY</code></a></li>
      <li><a name="toc-GIMPLE_005fWITH_005fCLEANUP_005fEXPR-1" href="GIMPLE_005fWITH_005fCLEANUP_005fEXPR.html#GIMPLE_005fWITH_005fCLEANUP_005fEXPR">12.8.29 <code>GIMPLE_WITH_CLEANUP_EXPR</code></a></li>
    </ul></li>
    <li><a name="toc-GIMPLE-sequences-1" href="GIMPLE-sequences.html#GIMPLE-sequences">12.9 GIMPLE sequences</a></li>
    <li><a name="toc-Sequence-iterators-1" href="Sequence-iterators.html#Sequence-iterators">12.10 Sequence iterators</a></li>
    <li><a name="toc-Adding-a-new-GIMPLE-statement-code-1" href="Adding-a-new-GIMPLE-statement-code.html#Adding-a-new-GIMPLE-statement-code">12.11 Adding a new GIMPLE statement code</a></li>
    <li><a name="toc-Statement-and-operand-traversals-1" href="Statement-and-operand-traversals.html#Statement-and-operand-traversals">12.12 Statement and operand traversals</a></li>
  </ul></li>
  <li><a name="toc-Analysis-and-Optimization-of-GIMPLE-tuples" href="Tree-SSA.html#Tree-SSA">13 Analysis and Optimization of GIMPLE tuples</a>
  <ul class="no-bullet">
    <li><a name="toc-Annotations-1" href="Annotations.html#Annotations">13.1 Annotations</a></li>
    <li><a name="toc-SSA-Operands-1" href="SSA-Operands.html#SSA-Operands">13.2 SSA Operands</a>
    <ul class="no-bullet">
      <li><a name="toc-Operand-Iterators-And-Access-Routines" href="SSA-Operands.html#Operand-Iterators-And-Access-Routines">13.2.1 Operand Iterators And Access Routines</a></li>
      <li><a name="toc-Immediate-Uses" href="SSA-Operands.html#Immediate-Uses">13.2.2 Immediate Uses</a></li>
    </ul></li>
    <li><a name="toc-Static-Single-Assignment" href="SSA.html#SSA">13.3 Static Single Assignment</a>
    <ul class="no-bullet">
      <li><a name="toc-Preserving-the-SSA-form" href="SSA.html#Preserving-the-SSA-form">13.3.1 Preserving the SSA form</a></li>
      <li><a name="toc-Examining-SSA_005fNAME-nodes" href="SSA.html#Examining-SSA_005fNAME-nodes">13.3.2 Examining <code>SSA_NAME</code> nodes</a></li>
      <li><a name="toc-Walking-the-dominator-tree" href="SSA.html#Walking-the-dominator-tree">13.3.3 Walking the dominator tree</a></li>
    </ul></li>
    <li><a name="toc-Alias-analysis-1" href="Alias-analysis.html#Alias-analysis">13.4 Alias analysis</a></li>
    <li><a name="toc-Memory-model-1" href="Memory-model.html#Memory-model">13.5 Memory model</a></li>
  </ul></li>
  <li><a name="toc-RTL-Representation" href="RTL.html#RTL">14 RTL Representation</a>
  <ul class="no-bullet">
    <li><a name="toc-RTL-Object-Types" href="RTL-Objects.html#RTL-Objects">14.1 RTL Object Types</a></li>
    <li><a name="toc-RTL-Classes-and-Formats" href="RTL-Classes.html#RTL-Classes">14.2 RTL Classes and Formats</a></li>
    <li><a name="toc-Access-to-Operands" href="Accessors.html#Accessors">14.3 Access to Operands</a></li>
    <li><a name="toc-Access-to-Special-Operands" href="Special-Accessors.html#Special-Accessors">14.4 Access to Special Operands</a></li>
    <li><a name="toc-Flags-in-an-RTL-Expression" href="Flags.html#Flags">14.5 Flags in an RTL Expression</a></li>
    <li><a name="toc-Machine-Modes-1" href="Machine-Modes.html#Machine-Modes">14.6 Machine Modes</a></li>
    <li><a name="toc-Constant-Expression-Types" href="Constants.html#Constants">14.7 Constant Expression Types</a></li>
    <li><a name="toc-Registers-and-Memory" href="Regs-and-Memory.html#Regs-and-Memory">14.8 Registers and Memory</a></li>
    <li><a name="toc-RTL-Expressions-for-Arithmetic" href="Arithmetic.html#Arithmetic">14.9 RTL Expressions for Arithmetic</a></li>
    <li><a name="toc-Comparison-Operations" href="Comparisons.html#Comparisons">14.10 Comparison Operations</a></li>
    <li><a name="toc-Bit_002dFields-1" href="Bit_002dFields.html#Bit_002dFields">14.11 Bit-Fields</a></li>
    <li><a name="toc-Vector-Operations-1" href="Vector-Operations.html#Vector-Operations">14.12 Vector Operations</a></li>
    <li><a name="toc-Conversions-1" href="Conversions.html#Conversions">14.13 Conversions</a></li>
    <li><a name="toc-Declarations-2" href="RTL-Declarations.html#RTL-Declarations">14.14 Declarations</a></li>
    <li><a name="toc-Side-Effect-Expressions" href="Side-Effects.html#Side-Effects">14.15 Side Effect Expressions</a></li>
    <li><a name="toc-Embedded-Side_002dEffects-on-Addresses" href="Incdec.html#Incdec">14.16 Embedded Side-Effects on Addresses</a></li>
    <li><a name="toc-Assembler-Instructions-as-Expressions" href="Assembler.html#Assembler">14.17 Assembler Instructions as Expressions</a></li>
    <li><a name="toc-Variable-Location-Debug-Information-in-RTL" href="Debug-Information.html#Debug-Information">14.18 Variable Location Debug Information in RTL</a></li>
    <li><a name="toc-Insns-1" href="Insns.html#Insns">14.19 Insns</a></li>
    <li><a name="toc-RTL-Representation-of-Function_002dCall-Insns" href="Calls.html#Calls">14.20 RTL Representation of Function-Call Insns</a></li>
    <li><a name="toc-On_002dthe_002dSide-SSA-Form-for-RTL" href="RTL-SSA.html#RTL-SSA">14.21 On-the-Side SSA Form for RTL</a>
    <ul class="no-bullet">
      <li><a name="toc-Using-RTL-SSA-in-a-pass" href="Using-RTL-SSA.html#Using-RTL-SSA">14.21.1 Using RTL SSA in a pass</a></li>
      <li><a name="toc-RTL-SSA-Instructions-1" href="RTL-SSA-Instructions.html#RTL-SSA-Instructions">14.21.2 RTL SSA Instructions</a></li>
      <li><a name="toc-RTL-SSA-Basic-Blocks-1" href="RTL-SSA-Basic-Blocks.html#RTL-SSA-Basic-Blocks">14.21.3 RTL SSA Basic Blocks</a></li>
      <li><a name="toc-RTL-SSA-Resources-1" href="RTL-SSA-Resources.html#RTL-SSA-Resources">14.21.4 RTL SSA Resources</a></li>
      <li><a name="toc-RTL-SSA-Register-and-Memory-Accesses" href="RTL-SSA-Accesses.html#RTL-SSA-Accesses">14.21.5 RTL SSA Register and Memory Accesses</a></li>
      <li><a name="toc-RTL-SSA-Phi-Nodes-1" href="RTL-SSA-Phi-Nodes.html#RTL-SSA-Phi-Nodes">14.21.6 RTL SSA Phi Nodes</a></li>
      <li><a name="toc-RTL-SSA-Access-Lists-1" href="RTL-SSA-Access-Lists.html#RTL-SSA-Access-Lists">14.21.7 RTL SSA Access Lists</a></li>
      <li><a name="toc-Using-the-RTL-SSA-framework-to-change-instructions" href="Changing-RTL-Instructions.html#Changing-RTL-Instructions">14.21.8 Using the RTL SSA framework to change instructions</a>
      <ul class="no-bullet">
        <li><a name="toc-Changing-One-RTL-SSA-Instruction-1" href="Changing-One-RTL-SSA-Instruction.html#Changing-One-RTL-SSA-Instruction">14.21.8.1 Changing One RTL SSA Instruction</a></li>
        <li><a name="toc-Changing-Multiple-RTL-SSA-Instructions-1" href="Changing-Multiple-RTL-SSA-Instructions.html#Changing-Multiple-RTL-SSA-Instructions">14.21.8.2 Changing Multiple RTL SSA Instructions</a></li>
      </ul></li>
    </ul></li>
    <li><a name="toc-Structure-Sharing-Assumptions" href="Sharing.html#Sharing">14.22 Structure Sharing Assumptions</a></li>
    <li><a name="toc-Reading-RTL-1" href="Reading-RTL.html#Reading-RTL">14.23 Reading RTL</a></li>
  </ul></li>
  <li><a name="toc-Control-Flow-Graph" href="Control-Flow.html#Control-Flow">15 Control Flow Graph</a>
  <ul class="no-bullet">
    <li><a name="toc-Basic-Blocks-1" href="Basic-Blocks.html#Basic-Blocks">15.1 Basic Blocks</a></li>
    <li><a name="toc-Edges-1" href="Edges.html#Edges">15.2 Edges</a></li>
    <li><a name="toc-Profile-information-1" href="Profile-information.html#Profile-information">15.3 Profile information</a></li>
    <li><a name="toc-Maintaining-the-CFG-1" href="Maintaining-the-CFG.html#Maintaining-the-CFG">15.4 Maintaining the CFG</a></li>
    <li><a name="toc-Liveness-information-1" href="Liveness-information.html#Liveness-information">15.5 Liveness information</a></li>
  </ul></li>
  <li><a name="toc-Analysis-and-Representation-of-Loops" href="Loop-Analysis-and-Representation.html#Loop-Analysis-and-Representation">16 Analysis and Representation of Loops</a>
  <ul class="no-bullet">
    <li><a name="toc-Loop-representation-1" href="Loop-representation.html#Loop-representation">16.1 Loop representation</a></li>
    <li><a name="toc-Loop-querying-1" href="Loop-querying.html#Loop-querying">16.2 Loop querying</a></li>
    <li><a name="toc-Loop-manipulation-1" href="Loop-manipulation.html#Loop-manipulation">16.3 Loop manipulation</a></li>
    <li><a name="toc-Loop_002dclosed-SSA-form" href="LCSSA.html#LCSSA">16.4 Loop-closed SSA form</a></li>
    <li><a name="toc-Scalar-evolutions-1" href="Scalar-evolutions.html#Scalar-evolutions">16.5 Scalar evolutions</a></li>
    <li><a name="toc-IV-analysis-on-RTL" href="loop_002div.html#loop_002div">16.6 IV analysis on RTL</a></li>
    <li><a name="toc-Number-of-iterations-analysis" href="Number-of-iterations.html#Number-of-iterations">16.7 Number of iterations analysis</a></li>
    <li><a name="toc-Data-Dependency-Analysis" href="Dependency-analysis.html#Dependency-analysis">16.8 Data Dependency Analysis</a></li>
  </ul></li>
  <li><a name="toc-Machine-Descriptions" href="Machine-Desc.html#Machine-Desc">17 Machine Descriptions</a>
  <ul class="no-bullet">
    <li><a name="toc-Overview-of-How-the-Machine-Description-is-Used" href="Overview.html#Overview">17.1 Overview of How the Machine Description is Used</a></li>
    <li><a name="toc-Everything-about-Instruction-Patterns" href="Patterns.html#Patterns">17.2 Everything about Instruction Patterns</a></li>
    <li><a name="toc-Example-of-define_005finsn" href="Example.html#Example">17.3 Example of <code>define_insn</code></a></li>
    <li><a name="toc-RTL-Template-1" href="RTL-Template.html#RTL-Template">17.4 RTL Template</a></li>
    <li><a name="toc-Output-Templates-and-Operand-Substitution" href="Output-Template.html#Output-Template">17.5 Output Templates and Operand Substitution</a></li>
    <li><a name="toc-C-Statements-for-Assembler-Output" href="Output-Statement.html#Output-Statement">17.6 C Statements for Assembler Output</a></li>
    <li><a name="toc-Predicates-1" href="Predicates.html#Predicates">17.7 Predicates</a>
    <ul class="no-bullet">
      <li><a name="toc-Machine_002dIndependent-Predicates-1" href="Machine_002dIndependent-Predicates.html#Machine_002dIndependent-Predicates">17.7.1 Machine-Independent Predicates</a></li>
      <li><a name="toc-Defining-Machine_002dSpecific-Predicates" href="Defining-Predicates.html#Defining-Predicates">17.7.2 Defining Machine-Specific Predicates</a></li>
    </ul></li>
    <li><a name="toc-Operand-Constraints" href="Constraints.html#Constraints">17.8 Operand Constraints</a>
    <ul class="no-bullet">
      <li><a name="toc-Simple-Constraints-1" href="Simple-Constraints.html#Simple-Constraints">17.8.1 Simple Constraints</a></li>
      <li><a name="toc-Multiple-Alternative-Constraints" href="Multi_002dAlternative.html#Multi_002dAlternative">17.8.2 Multiple Alternative Constraints</a></li>
      <li><a name="toc-Register-Class-Preferences" href="Class-Preferences.html#Class-Preferences">17.8.3 Register Class Preferences</a></li>
      <li><a name="toc-Constraint-Modifier-Characters" href="Modifiers.html#Modifiers">17.8.4 Constraint Modifier Characters</a></li>
      <li><a name="toc-Constraints-for-Particular-Machines" href="Machine-Constraints.html#Machine-Constraints">17.8.5 Constraints for Particular Machines</a></li>
      <li><a name="toc-Disable-insn-alternatives-using-the-enabled-attribute" href="Disable-Insn-Alternatives.html#Disable-Insn-Alternatives">17.8.6 Disable insn alternatives using the <code>enabled</code> attribute</a></li>
      <li><a name="toc-Defining-Machine_002dSpecific-Constraints" href="Define-Constraints.html#Define-Constraints">17.8.7 Defining Machine-Specific Constraints</a></li>
      <li><a name="toc-Testing-constraints-from-C" href="C-Constraint-Interface.html#C-Constraint-Interface">17.8.8 Testing constraints from C</a></li>
    </ul></li>
    <li><a name="toc-Standard-Pattern-Names-For-Generation" href="Standard-Names.html#Standard-Names">17.9 Standard Pattern Names For Generation</a></li>
    <li><a name="toc-When-the-Order-of-Patterns-Matters" href="Pattern-Ordering.html#Pattern-Ordering">17.10 When the Order of Patterns Matters</a></li>
    <li><a name="toc-Interdependence-of-Patterns" href="Dependent-Patterns.html#Dependent-Patterns">17.11 Interdependence of Patterns</a></li>
    <li><a name="toc-Defining-Jump-Instruction-Patterns" href="Jump-Patterns.html#Jump-Patterns">17.12 Defining Jump Instruction Patterns</a></li>
    <li><a name="toc-Defining-Looping-Instruction-Patterns" href="Looping-Patterns.html#Looping-Patterns">17.13 Defining Looping Instruction Patterns</a></li>
    <li><a name="toc-Canonicalization-of-Instructions" href="Insn-Canonicalizations.html#Insn-Canonicalizations">17.14 Canonicalization of Instructions</a></li>
    <li><a name="toc-Defining-RTL-Sequences-for-Code-Generation" href="Expander-Definitions.html#Expander-Definitions">17.15 Defining RTL Sequences for Code Generation</a></li>
    <li><a name="toc-Defining-How-to-Split-Instructions" href="Insn-Splitting.html#Insn-Splitting">17.16 Defining How to Split Instructions</a></li>
    <li><a name="toc-Including-Patterns-in-Machine-Descriptions_002e" href="Including-Patterns.html#Including-Patterns">17.17 Including Patterns in Machine Descriptions.</a>
    <ul class="no-bullet">
      <li><a name="toc-RTL-Generation-Tool-Options-for-Directory-Search" href="Including-Patterns.html#RTL-Generation-Tool-Options-for-Directory-Search">17.17.1 RTL Generation Tool Options for Directory Search</a></li>
    </ul></li>
    <li><a name="toc-Machine_002dSpecific-Peephole-Optimizers" href="Peephole-Definitions.html#Peephole-Definitions">17.18 Machine-Specific Peephole Optimizers</a>
    <ul class="no-bullet">
      <li><a name="toc-RTL-to-Text-Peephole-Optimizers" href="define_005fpeephole.html#define_005fpeephole">17.18.1 RTL to Text Peephole Optimizers</a></li>
      <li><a name="toc-RTL-to-RTL-Peephole-Optimizers" href="define_005fpeephole2.html#define_005fpeephole2">17.18.2 RTL to RTL Peephole Optimizers</a></li>
    </ul></li>
    <li><a name="toc-Instruction-Attributes" href="Insn-Attributes.html#Insn-Attributes">17.19 Instruction Attributes</a>
    <ul class="no-bullet">
      <li><a name="toc-Defining-Attributes-and-their-Values" href="Defining-Attributes.html#Defining-Attributes">17.19.1 Defining Attributes and their Values</a></li>
      <li><a name="toc-Attribute-Expressions" href="Expressions.html#Expressions">17.19.2 Attribute Expressions</a></li>
      <li><a name="toc-Assigning-Attribute-Values-to-Insns" href="Tagging-Insns.html#Tagging-Insns">17.19.3 Assigning Attribute Values to Insns</a></li>
      <li><a name="toc-Example-of-Attribute-Specifications" href="Attr-Example.html#Attr-Example">17.19.4 Example of Attribute Specifications</a></li>
      <li><a name="toc-Computing-the-Length-of-an-Insn" href="Insn-Lengths.html#Insn-Lengths">17.19.5 Computing the Length of an Insn</a></li>
      <li><a name="toc-Constant-Attributes-1" href="Constant-Attributes.html#Constant-Attributes">17.19.6 Constant Attributes</a></li>
      <li><a name="toc-Mnemonic-Attribute-1" href="Mnemonic-Attribute.html#Mnemonic-Attribute">17.19.7 Mnemonic Attribute</a></li>
      <li><a name="toc-Delay-Slot-Scheduling" href="Delay-Slots.html#Delay-Slots">17.19.8 Delay Slot Scheduling</a></li>
      <li><a name="toc-Specifying-processor-pipeline-description" href="Processor-pipeline-description.html#Processor-pipeline-description">17.19.9 Specifying processor pipeline description</a></li>
    </ul></li>
    <li><a name="toc-Conditional-Execution-1" href="Conditional-Execution.html#Conditional-Execution">17.20 Conditional Execution</a></li>
    <li><a name="toc-RTL-Templates-Transformations" href="Define-Subst.html#Define-Subst">17.21 RTL Templates Transformations</a>
    <ul class="no-bullet">
      <li><a name="toc-define_005fsubst-Example" href="Define-Subst-Example.html#Define-Subst-Example">17.21.1 <code>define_subst</code> Example</a></li>
      <li><a name="toc-Pattern-Matching-in-define_005fsubst" href="Define-Subst-Pattern-Matching.html#Define-Subst-Pattern-Matching">17.21.2 Pattern Matching in <code>define_subst</code></a></li>
      <li><a name="toc-Generation-of-output-template-in-define_005fsubst" href="Define-Subst-Output-Template.html#Define-Subst-Output-Template">17.21.3 Generation of output template in <code>define_subst</code></a></li>
    </ul></li>
    <li><a name="toc-Constant-Definitions-1" href="Constant-Definitions.html#Constant-Definitions">17.22 Constant Definitions</a></li>
    <li><a name="toc-Iterators-1" href="Iterators.html#Iterators">17.23 Iterators</a>
    <ul class="no-bullet">
      <li><a name="toc-Mode-Iterators-1" href="Mode-Iterators.html#Mode-Iterators">17.23.1 Mode Iterators</a>
      <ul class="no-bullet">
        <li><a name="toc-Defining-Mode-Iterators-1" href="Defining-Mode-Iterators.html#Defining-Mode-Iterators">17.23.1.1 Defining Mode Iterators</a></li>
        <li><a name="toc-Substitution-in-Mode-Iterators" href="Substitutions.html#Substitutions">17.23.1.2 Substitution in Mode Iterators</a></li>
        <li><a name="toc-Mode-Iterator-Examples" href="Examples.html#Examples">17.23.1.3 Mode Iterator Examples</a></li>
      </ul></li>
      <li><a name="toc-Code-Iterators-1" href="Code-Iterators.html#Code-Iterators">17.23.2 Code Iterators</a></li>
      <li><a name="toc-Int-Iterators-1" href="Int-Iterators.html#Int-Iterators">17.23.3 Int Iterators</a></li>
      <li><a name="toc-Subst-Iterators-1" href="Subst-Iterators.html#Subst-Iterators">17.23.4 Subst Iterators</a></li>
      <li><a name="toc-Parameterized-Names-1" href="Parameterized-Names.html#Parameterized-Names">17.23.5 Parameterized Names</a></li>
    </ul></li>
  </ul></li>
  <li><a name="toc-Target-Description-Macros-and-Functions" href="Target-Macros.html#Target-Macros">18 Target Description Macros and Functions</a>
  <ul class="no-bullet">
    <li><a name="toc-The-Global-targetm-Variable" href="Target-Structure.html#Target-Structure">18.1 The Global <code>targetm</code> Variable</a></li>
    <li><a name="toc-Controlling-the-Compilation-Driver_002c-gcc" href="Driver.html#Driver">18.2 Controlling the Compilation Driver, <samp>gcc</samp></a></li>
    <li><a name="toc-Run_002dtime-Target-Specification" href="Run_002dtime-Target.html#Run_002dtime-Target">18.3 Run-time Target Specification</a></li>
    <li><a name="toc-Defining-data-structures-for-per_002dfunction-information_002e" href="Per_002dFunction-Data.html#Per_002dFunction-Data">18.4 Defining data structures for per-function information.</a></li>
    <li><a name="toc-Storage-Layout-1" href="Storage-Layout.html#Storage-Layout">18.5 Storage Layout</a></li>
    <li><a name="toc-Layout-of-Source-Language-Data-Types" href="Type-Layout.html#Type-Layout">18.6 Layout of Source Language Data Types</a></li>
    <li><a name="toc-Register-Usage" href="Registers.html#Registers">18.7 Register Usage</a>
    <ul class="no-bullet">
      <li><a name="toc-Basic-Characteristics-of-Registers" href="Register-Basics.html#Register-Basics">18.7.1 Basic Characteristics of Registers</a></li>
      <li><a name="toc-Order-of-Allocation-of-Registers" href="Allocation-Order.html#Allocation-Order">18.7.2 Order of Allocation of Registers</a></li>
      <li><a name="toc-How-Values-Fit-in-Registers" href="Values-in-Registers.html#Values-in-Registers">18.7.3 How Values Fit in Registers</a></li>
      <li><a name="toc-Handling-Leaf-Functions" href="Leaf-Functions.html#Leaf-Functions">18.7.4 Handling Leaf Functions</a></li>
      <li><a name="toc-Registers-That-Form-a-Stack" href="Stack-Registers.html#Stack-Registers">18.7.5 Registers That Form a Stack</a></li>
    </ul></li>
    <li><a name="toc-Register-Classes-1" href="Register-Classes.html#Register-Classes">18.8 Register Classes</a></li>
    <li><a name="toc-Stack-Layout-and-Calling-Conventions" href="Stack-and-Calling.html#Stack-and-Calling">18.9 Stack Layout and Calling Conventions</a>
    <ul class="no-bullet">
      <li><a name="toc-Basic-Stack-Layout" href="Frame-Layout.html#Frame-Layout">18.9.1 Basic Stack Layout</a></li>
      <li><a name="toc-Exception-Handling-Support" href="Exception-Handling.html#Exception-Handling">18.9.2 Exception Handling Support</a></li>
      <li><a name="toc-Specifying-How-Stack-Checking-is-Done" href="Stack-Checking.html#Stack-Checking">18.9.3 Specifying How Stack Checking is Done</a></li>
      <li><a name="toc-Registers-That-Address-the-Stack-Frame" href="Frame-Registers.html#Frame-Registers">18.9.4 Registers That Address the Stack Frame</a></li>
      <li><a name="toc-Eliminating-Frame-Pointer-and-Arg-Pointer" href="Elimination.html#Elimination">18.9.5 Eliminating Frame Pointer and Arg Pointer</a></li>
      <li><a name="toc-Passing-Function-Arguments-on-the-Stack" href="Stack-Arguments.html#Stack-Arguments">18.9.6 Passing Function Arguments on the Stack</a></li>
      <li><a name="toc-Passing-Arguments-in-Registers" href="Register-Arguments.html#Register-Arguments">18.9.7 Passing Arguments in Registers</a></li>
      <li><a name="toc-How-Scalar-Function-Values-Are-Returned" href="Scalar-Return.html#Scalar-Return">18.9.8 How Scalar Function Values Are Returned</a></li>
      <li><a name="toc-How-Large-Values-Are-Returned" href="Aggregate-Return.html#Aggregate-Return">18.9.9 How Large Values Are Returned</a></li>
      <li><a name="toc-Caller_002dSaves-Register-Allocation" href="Caller-Saves.html#Caller-Saves">18.9.10 Caller-Saves Register Allocation</a></li>
      <li><a name="toc-Function-Entry-and-Exit" href="Function-Entry.html#Function-Entry">18.9.11 Function Entry and Exit</a></li>
      <li><a name="toc-Generating-Code-for-Profiling" href="Profiling.html#Profiling">18.9.12 Generating Code for Profiling</a></li>
      <li><a name="toc-Permitting-tail-calls" href="Tail-Calls.html#Tail-Calls">18.9.13 Permitting tail calls</a></li>
      <li><a name="toc-Shrink_002dwrapping-separate-components-1" href="Shrink_002dwrapping-separate-components.html#Shrink_002dwrapping-separate-components">18.9.14 Shrink-wrapping separate components</a></li>
      <li><a name="toc-Stack-smashing-protection" href="Stack-Smashing-Protection.html#Stack-Smashing-Protection">18.9.15 Stack smashing protection</a></li>
      <li><a name="toc-Miscellaneous-register-hooks" href="Miscellaneous-Register-Hooks.html#Miscellaneous-Register-Hooks">18.9.16 Miscellaneous register hooks</a></li>
    </ul></li>
    <li><a name="toc-Implementing-the-Varargs-Macros" href="Varargs.html#Varargs">18.10 Implementing the Varargs Macros</a></li>
    <li><a name="toc-Support-for-Nested-Functions" href="Trampolines.html#Trampolines">18.11 Support for Nested Functions</a></li>
    <li><a name="toc-Implicit-Calls-to-Library-Routines" href="Library-Calls.html#Library-Calls">18.12 Implicit Calls to Library Routines</a></li>
    <li><a name="toc-Addressing-Modes-1" href="Addressing-Modes.html#Addressing-Modes">18.13 Addressing Modes</a></li>
    <li><a name="toc-Anchored-Addresses-1" href="Anchored-Addresses.html#Anchored-Addresses">18.14 Anchored Addresses</a></li>
    <li><a name="toc-Condition-Code-Status" href="Condition-Code.html#Condition-Code">18.15 Condition Code Status</a>
    <ul class="no-bullet">
      <li><a name="toc-Representation-of-condition-codes-using-registers" href="MODE_005fCC-Condition-Codes.html#MODE_005fCC-Condition-Codes">18.15.1 Representation of condition codes using registers</a></li>
    </ul></li>
    <li><a name="toc-Describing-Relative-Costs-of-Operations" href="Costs.html#Costs">18.16 Describing Relative Costs of Operations</a></li>
    <li><a name="toc-Adjusting-the-Instruction-Scheduler" href="Scheduling.html#Scheduling">18.17 Adjusting the Instruction Scheduler</a></li>
    <li><a name="toc-Dividing-the-Output-into-Sections-_0028Texts_002c-Data_002c-_2026_0029" href="Sections.html#Sections">18.18 Dividing the Output into Sections (Texts, Data, &hellip;)</a></li>
    <li><a name="toc-Position-Independent-Code" href="PIC.html#PIC">18.19 Position Independent Code</a></li>
    <li><a name="toc-Defining-the-Output-Assembler-Language" href="Assembler-Format.html#Assembler-Format">18.20 Defining the Output Assembler Language</a>
    <ul class="no-bullet">
      <li><a name="toc-The-Overall-Framework-of-an-Assembler-File" href="File-Framework.html#File-Framework">18.20.1 The Overall Framework of an Assembler File</a></li>
      <li><a name="toc-Output-of-Data" href="Data-Output.html#Data-Output">18.20.2 Output of Data</a></li>
      <li><a name="toc-Output-of-Uninitialized-Variables" href="Uninitialized-Data.html#Uninitialized-Data">18.20.3 Output of Uninitialized Variables</a></li>
      <li><a name="toc-Output-and-Generation-of-Labels" href="Label-Output.html#Label-Output">18.20.4 Output and Generation of Labels</a></li>
      <li><a name="toc-How-Initialization-Functions-Are-Handled" href="Initialization.html#Initialization">18.20.5 How Initialization Functions Are Handled</a></li>
      <li><a name="toc-Macros-Controlling-Initialization-Routines" href="Macros-for-Initialization.html#Macros-for-Initialization">18.20.6 Macros Controlling Initialization Routines</a></li>
      <li><a name="toc-Output-of-Assembler-Instructions" href="Instruction-Output.html#Instruction-Output">18.20.7 Output of Assembler Instructions</a></li>
      <li><a name="toc-Output-of-Dispatch-Tables" href="Dispatch-Tables.html#Dispatch-Tables">18.20.8 Output of Dispatch Tables</a></li>
      <li><a name="toc-Assembler-Commands-for-Exception-Regions" href="Exception-Region-Output.html#Exception-Region-Output">18.20.9 Assembler Commands for Exception Regions</a></li>
      <li><a name="toc-Assembler-Commands-for-Alignment" href="Alignment-Output.html#Alignment-Output">18.20.10 Assembler Commands for Alignment</a></li>
    </ul></li>
    <li><a name="toc-Controlling-Debugging-Information-Format" href="Debugging-Info.html#Debugging-Info">18.21 Controlling Debugging Information Format</a>
    <ul class="no-bullet">
      <li><a name="toc-Macros-Affecting-All-Debugging-Formats" href="All-Debuggers.html#All-Debuggers">18.21.1 Macros Affecting All Debugging Formats</a></li>
      <li><a name="toc-Macros-for-DWARF-Output" href="DWARF.html#DWARF">18.21.2 Macros for DWARF Output</a></li>
      <li><a name="toc-Macros-for-VMS-Debug-Format" href="VMS-Debug.html#VMS-Debug">18.21.3 Macros for VMS Debug Format</a></li>
      <li><a name="toc-Macros-for-CTF-Debug-Format" href="CTF-Debug.html#CTF-Debug">18.21.4 Macros for CTF Debug Format</a></li>
      <li><a name="toc-Macros-for-BTF-Debug-Format" href="BTF-Debug.html#BTF-Debug">18.21.5 Macros for BTF Debug Format</a></li>
    </ul></li>
    <li><a name="toc-Cross-Compilation-and-Floating-Point" href="Floating-Point.html#Floating-Point">18.22 Cross Compilation and Floating Point</a></li>
    <li><a name="toc-Mode-Switching-Instructions" href="Mode-Switching.html#Mode-Switching">18.23 Mode Switching Instructions</a></li>
    <li><a name="toc-Defining-target_002dspecific-uses-of-_005f_005fattribute_005f_005f" href="Target-Attributes.html#Target-Attributes">18.24 Defining target-specific uses of <code>__attribute__</code></a></li>
    <li><a name="toc-Emulating-TLS" href="Emulated-TLS.html#Emulated-TLS">18.25 Emulating TLS</a></li>
    <li><a name="toc-Defining-coprocessor-specifics-for-MIPS-targets_002e" href="MIPS-Coprocessors.html#MIPS-Coprocessors">18.26 Defining coprocessor specifics for MIPS targets.</a></li>
    <li><a name="toc-Parameters-for-Precompiled-Header-Validity-Checking" href="PCH-Target.html#PCH-Target">18.27 Parameters for Precompiled Header Validity Checking</a></li>
    <li><a name="toc-C_002b_002b-ABI-parameters" href="C_002b_002b-ABI.html#C_002b_002b-ABI">18.28 C++ ABI parameters</a></li>
    <li><a name="toc-D-ABI-parameters" href="D-Language-and-ABI.html#D-Language-and-ABI">18.29 D ABI parameters</a></li>
    <li><a name="toc-Adding-support-for-named-address-spaces" href="Named-Address-Spaces.html#Named-Address-Spaces">18.30 Adding support for named address spaces</a></li>
    <li><a name="toc-Miscellaneous-Parameters" href="Misc.html#Misc">18.31 Miscellaneous Parameters</a></li>
  </ul></li>
  <li><a name="toc-Host-Configuration" href="Host-Config.html#Host-Config">19 Host Configuration</a>
  <ul class="no-bullet">
    <li><a name="toc-Host-Common-1" href="Host-Common.html#Host-Common">19.1 Host Common</a></li>
    <li><a name="toc-Host-Filesystem" href="Filesystem.html#Filesystem">19.2 Host Filesystem</a></li>
    <li><a name="toc-Host-Misc-1" href="Host-Misc.html#Host-Misc">19.3 Host Misc</a></li>
  </ul></li>
  <li><a name="toc-Makefile-Fragments" href="Fragments.html#Fragments">20 Makefile Fragments</a>
  <ul class="no-bullet">
    <li><a name="toc-Target-Makefile-Fragments" href="Target-Fragment.html#Target-Fragment">20.1 Target Makefile Fragments</a></li>
    <li><a name="toc-Host-Makefile-Fragments" href="Host-Fragment.html#Host-Fragment">20.2 Host Makefile Fragments</a></li>
  </ul></li>
  <li><a name="toc-collect2" href="Collect2.html#Collect2">21 <code>collect2</code></a></li>
  <li><a name="toc-Standard-Header-File-Directories" href="Header-Dirs.html#Header-Dirs">22 Standard Header File Directories</a></li>
  <li><a name="toc-Memory-Management-and-Type-Information" href="Type-Information.html#Type-Information">23 Memory Management and Type Information</a>
  <ul class="no-bullet">
    <li><a name="toc-The-Inside-of-a-GTY_0028_0028_0029_0029" href="GTY-Options.html#GTY-Options">23.1 The Inside of a <code>GTY(())</code></a></li>
    <li><a name="toc-Support-for-inheritance" href="Inheritance-and-GTY.html#Inheritance-and-GTY">23.2 Support for inheritance</a></li>
    <li><a name="toc-Support-for-user_002dprovided-GC-marking-routines" href="User-GC.html#User-GC">23.3 Support for user-provided GC marking routines</a>
    <ul class="no-bullet">
      <li><a name="toc-User_002dprovided-marking-routines-for-template-types" href="User-GC.html#User_002dprovided-marking-routines-for-template-types">23.3.1 User-provided marking routines for template types</a></li>
    </ul></li>
    <li><a name="toc-Marking-Roots-for-the-Garbage-Collector" href="GGC-Roots.html#GGC-Roots">23.4 Marking Roots for the Garbage Collector</a></li>
    <li><a name="toc-Source-Files-Containing-Type-Information" href="Files.html#Files">23.5 Source Files Containing Type Information</a></li>
    <li><a name="toc-How-to-invoke-the-garbage-collector" href="Invoking-the-garbage-collector.html#Invoking-the-garbage-collector">23.6 How to invoke the garbage collector</a></li>
    <li><a name="toc-Troubleshooting-the-garbage-collector" href="Troubleshooting.html#Troubleshooting">23.7 Troubleshooting the garbage collector</a></li>
  </ul></li>
  <li><a name="toc-Plugins-1" href="Plugins.html#Plugins">24 Plugins</a>
  <ul class="no-bullet">
    <li><a name="toc-Loading-Plugins" href="Plugins-loading.html#Plugins-loading">24.1 Loading Plugins</a></li>
    <li><a name="toc-Plugin-API-1" href="Plugin-API.html#Plugin-API">24.2 Plugin API</a>
    <ul class="no-bullet">
      <li><a name="toc-Plugin-license-check" href="Plugin-API.html#Plugin-license-check">24.2.1 Plugin license check</a></li>
      <li><a name="toc-Plugin-initialization" href="Plugin-API.html#Plugin-initialization">24.2.2 Plugin initialization</a></li>
      <li><a name="toc-Plugin-callbacks" href="Plugin-API.html#Plugin-callbacks">24.2.3 Plugin callbacks</a></li>
    </ul></li>
    <li><a name="toc-Interacting-with-the-pass-manager" href="Plugins-pass.html#Plugins-pass">24.3 Interacting with the pass manager</a></li>
    <li><a name="toc-Interacting-with-the-GCC-Garbage-Collector" href="Plugins-GC.html#Plugins-GC">24.4 Interacting with the GCC Garbage Collector</a></li>
    <li><a name="toc-Giving-information-about-a-plugin" href="Plugins-description.html#Plugins-description">24.5 Giving information about a plugin</a></li>
    <li><a name="toc-Registering-custom-attributes-or-pragmas" href="Plugins-attr.html#Plugins-attr">24.6 Registering custom attributes or pragmas</a></li>
    <li><a name="toc-Recording-information-about-pass-execution" href="Plugins-recording.html#Plugins-recording">24.7 Recording information about pass execution</a></li>
    <li><a name="toc-Controlling-which-passes-are-being-run" href="Plugins-gate.html#Plugins-gate">24.8 Controlling which passes are being run</a></li>
    <li><a name="toc-Keeping-track-of-available-passes" href="Plugins-tracking.html#Plugins-tracking">24.9 Keeping track of available passes</a></li>
    <li><a name="toc-Building-GCC-plugins" href="Plugins-building.html#Plugins-building">24.10 Building GCC plugins</a></li>
  </ul></li>
  <li><a name="toc-Link-Time-Optimization" href="LTO.html#LTO">25 Link Time Optimization</a>
  <ul class="no-bullet">
    <li><a name="toc-Design-Overview" href="LTO-Overview.html#LTO-Overview">25.1 Design Overview</a>
    <ul class="no-bullet">
      <li><a name="toc-LTO-modes-of-operation" href="LTO-Overview.html#LTO-modes-of-operation">25.1.1 LTO modes of operation</a></li>
    </ul></li>
    <li><a name="toc-LTO-file-sections" href="LTO-object-file-layout.html#LTO-object-file-layout">25.2 LTO file sections</a></li>
    <li><a name="toc-Using-summary-information-in-IPA-passes" href="IPA.html#IPA">25.3 Using summary information in IPA passes</a>
    <ul class="no-bullet">
      <li><a name="toc-Virtual-clones" href="IPA.html#Virtual-clones">25.3.1 Virtual clones</a></li>
      <li><a name="toc-IPA-references" href="IPA.html#IPA-references">25.3.2 IPA references</a></li>
      <li><a name="toc-Jump-functions" href="IPA.html#Jump-functions">25.3.3 Jump functions</a></li>
    </ul></li>
    <li><a name="toc-Whole-program-assumptions_002c-linker-plugin-and-symbol-visibilities" href="WHOPR.html#WHOPR">25.4 Whole program assumptions, linker plugin and symbol visibilities</a></li>
    <li><a name="toc-Internal-flags-controlling-lto1" href="Internal-flags.html#Internal-flags">25.5 Internal flags controlling <code>lto1</code></a></li>
  </ul></li>
  <li><a name="toc-Match-and-Simplify-1" href="Match-and-Simplify.html#Match-and-Simplify">26 Match and Simplify</a>
  <ul class="no-bullet">
    <li><a name="toc-GIMPLE-API-1" href="GIMPLE-API.html#GIMPLE-API">26.1 GIMPLE API</a></li>
    <li><a name="toc-The-Language-1" href="The-Language.html#The-Language">26.2 The Language</a></li>
  </ul></li>
  <li><a name="toc-Static-Analyzer-1" href="Static-Analyzer.html#Static-Analyzer">27 Static Analyzer</a>
  <ul class="no-bullet">
    <li><a name="toc-Analyzer-Internals-1" href="Analyzer-Internals.html#Analyzer-Internals">27.1 Analyzer Internals</a>
    <ul class="no-bullet">
      <li><a name="toc-Overview-2" href="Analyzer-Internals.html#Overview-2">27.1.1 Overview</a></li>
      <li><a name="toc-Graphs" href="Analyzer-Internals.html#Graphs">27.1.2 Graphs</a></li>
      <li><a name="toc-State-Tracking" href="Analyzer-Internals.html#State-Tracking">27.1.3 State Tracking</a></li>
      <li><a name="toc-Region-Model" href="Analyzer-Internals.html#Region-Model">27.1.4 Region Model</a></li>
      <li><a name="toc-Analyzer-Paths" href="Analyzer-Internals.html#Analyzer-Paths">27.1.5 Analyzer Paths</a></li>
      <li><a name="toc-Limitations" href="Analyzer-Internals.html#Limitations">27.1.6 Limitations</a></li>
    </ul></li>
    <li><a name="toc-Debugging-the-Analyzer-1" href="Debugging-the-Analyzer.html#Debugging-the-Analyzer">27.2 Debugging the Analyzer</a>
    <ul class="no-bullet">
      <li><a name="toc-Special-Functions-for-Debugging-the-Analyzer" href="Debugging-the-Analyzer.html#Special-Functions-for-Debugging-the-Analyzer">27.2.1 Special Functions for Debugging the Analyzer</a></li>
      <li><a name="toc-Other-Debugging-Techniques" href="Debugging-the-Analyzer.html#Other-Debugging-Techniques">27.2.2 Other Debugging Techniques</a></li>
    </ul></li>
  </ul></li>
  <li><a name="toc-User-Experience-Guidelines-1" href="User-Experience-Guidelines.html#User-Experience-Guidelines">28 User Experience Guidelines</a>
  <ul class="no-bullet">
    <li><a name="toc-Guidelines-for-Diagnostics-1" href="Guidelines-for-Diagnostics.html#Guidelines-for-Diagnostics">28.1 Guidelines for Diagnostics</a>
    <ul class="no-bullet">
      <li><a name="toc-Talk-in-terms-of-the-user_0027s-code" href="Guidelines-for-Diagnostics.html#Talk-in-terms-of-the-user_0027s-code">28.1.1 Talk in terms of the user&rsquo;s code</a></li>
      <li><a name="toc-Diagnostics-are-actionable" href="Guidelines-for-Diagnostics.html#Diagnostics-are-actionable">28.1.2 Diagnostics are actionable</a></li>
      <li><a name="toc-The-user_0027s-attention-is-important" href="Guidelines-for-Diagnostics.html#The-user_0027s-attention-is-important">28.1.3 The user&rsquo;s attention is important</a></li>
      <li><a name="toc-Sometimes-the-user-didn_0027t-write-the-code" href="Guidelines-for-Diagnostics.html#Sometimes-the-user-didn_0027t-write-the-code">28.1.4 Sometimes the user didn&rsquo;t write the code</a></li>
      <li><a name="toc-Precision-of-Wording" href="Guidelines-for-Diagnostics.html#Precision-of-Wording">28.1.5 Precision of Wording</a></li>
      <li><a name="toc-Try-the-diagnostic-on-real_002dworld-code" href="Guidelines-for-Diagnostics.html#Try-the-diagnostic-on-real_002dworld-code">28.1.6 Try the diagnostic on real-world code</a></li>
      <li><a name="toc-Make-mismatches-clear" href="Guidelines-for-Diagnostics.html#Make-mismatches-clear">28.1.7 Make mismatches clear</a></li>
      <li><a name="toc-Location-Information" href="Guidelines-for-Diagnostics.html#Location-Information">28.1.8 Location Information</a></li>
      <li><a name="toc-Coding-Conventions" href="Guidelines-for-Diagnostics.html#Coding-Conventions">28.1.9 Coding Conventions</a></li>
      <li><a name="toc-Group-logically_002drelated-diagnostics" href="Guidelines-for-Diagnostics.html#Group-logically_002drelated-diagnostics">28.1.10 Group logically-related diagnostics</a></li>
      <li><a name="toc-Quoting" href="Guidelines-for-Diagnostics.html#Quoting">28.1.11 Quoting</a></li>
      <li><a name="toc-Spelling-and-Terminology" href="Guidelines-for-Diagnostics.html#Spelling-and-Terminology">28.1.12 Spelling and Terminology</a></li>
      <li><a name="toc-Fix_002dit-hints" href="Guidelines-for-Diagnostics.html#Fix_002dit-hints">28.1.13 Fix-it hints</a>
      <ul class="no-bullet">
        <li><a name="toc-Fix_002dit-hints-should-work" href="Guidelines-for-Diagnostics.html#Fix_002dit-hints-should-work">28.1.13.1 Fix-it hints should work</a></li>
        <li><a name="toc-Express-deletion-in-terms-of-deletion_002c-not-replacement" href="Guidelines-for-Diagnostics.html#Express-deletion-in-terms-of-deletion_002c-not-replacement">28.1.13.2 Express deletion in terms of deletion, not replacement</a></li>
        <li><a name="toc-Multiple-suggestions" href="Guidelines-for-Diagnostics.html#Multiple-suggestions">28.1.13.3 Multiple suggestions</a></li>
      </ul></li>
    </ul></li>
    <li><a name="toc-Guidelines-for-Options-1" href="Guidelines-for-Options.html#Guidelines-for-Options">28.2 Guidelines for Options</a></li>
  </ul></li>
  <li><a name="toc-Funding-Free-Software" href="Funding.html#Funding">Funding Free Software</a></li>
  <li><a name="toc-The-GNU-Project-and-GNU_002fLinux" href="GNU-Project.html#GNU-Project">The GNU Project and GNU/Linux</a></li>
  <li><a name="toc-GNU-General-Public-License" href="Copying.html#Copying">GNU General Public License</a></li>
  <li><a name="toc-GNU-Free-Documentation-License-1" href="GNU-Free-Documentation-License.html#GNU-Free-Documentation-License">GNU Free Documentation License</a>
  <ul class="no-bullet">
    <li><a name="toc-ADDENDUM_003a-How-to-use-this-License-for-your-documents" href="GNU-Free-Documentation-License.html#ADDENDUM_003a-How-to-use-this-License-for-your-documents">ADDENDUM: How to use this License for your documents</a></li>
  </ul></li>
  <li><a name="toc-Contributors-to-GCC" href="Contributors.html#Contributors">Contributors to GCC</a></li>
  <li><a name="toc-Option-Index-1" href="Option-Index.html#Option-Index">Option Index</a></li>
  <li><a name="toc-Concept-Index-1" href="Concept-Index.html#Concept-Index">Concept Index</a></li>
</ul>
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<div class="header">
<p>
Next: <a href="Contributing.html#Contributing" accesskey="n" rel="next">Contributing</a> &nbsp; [<a href="#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Option-Index.html#Option-Index" title="Index" rel="index">Index</a>]</p>
</div>
<hr>
<a name="Introduction"></a>
<h1 class="top">Introduction</h1>
<a name="index-introduction"></a>

<p>This manual documents the internals of the GNU compilers, including
how to port them to new targets and some information about how to
write front ends for new languages.  It corresponds to the compilers
(Arm GNU Toolchain 13.2.rel1 (Build arm-13.7))
version 13.2.1.  The use of the GNU compilers is documented in a
separate manual.  See <a href="../gcc/index.html#Top">Introduction</a> in <cite>Using the GNU
Compiler Collection (GCC)</cite>.
</p>
<p>This manual is mainly a reference manual rather than a tutorial.  It
discusses how to contribute to GCC (see <a href="Contributing.html#Contributing">Contributing</a>), the
characteristics of the machines supported by GCC as hosts and targets
(see <a href="Portability.html#Portability">Portability</a>), how GCC relates to the ABIs on such systems
(see <a href="Interface.html#Interface">Interface</a>), and the characteristics of the languages for
which GCC front ends are written (see <a href="Languages.html#Languages">Languages</a>).  It then
describes the GCC source tree structure and build system, some of the
interfaces to GCC front ends, and how support for a target system is
implemented in GCC.
</p>
<p>Additional tutorial information is linked to from
<a href="https://gcc.gnu.org/readings.html">https://gcc.gnu.org/readings.html</a>.
</p>
<table class="menu" border="0" cellspacing="0">
<tr><td align="left" valign="top">&bull; <a href="Contributing.html#Contributing" accesskey="1">Contributing</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">How to contribute to testing and developing GCC.
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="Portability.html#Portability" accesskey="2">Portability</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Goals of GCC&rsquo;s portability features.
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="Interface.html#Interface" accesskey="3">Interface</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Function-call interface of GCC output.
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="Libgcc.html#Libgcc" accesskey="4">Libgcc</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Low-level runtime library used by GCC.
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="Languages.html#Languages" accesskey="5">Languages</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Languages for which GCC front ends are written.
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="Source-Tree.html#Source-Tree" accesskey="6">Source Tree</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">GCC source tree structure and build system.
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="Testsuites.html#Testsuites" accesskey="7">Testsuites</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">GCC testsuites.
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="Options.html#Options" accesskey="8">Options</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Option specification files.
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="Passes.html#Passes" accesskey="9">Passes</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Order of passes, what they do, and what each file is for.
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="poly_005fint.html#poly_005fint">poly_int</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Representation of runtime sizes and offsets.
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="GENERIC.html#GENERIC">GENERIC</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Language-independent representation generated by Front Ends
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="GIMPLE.html#GIMPLE">GIMPLE</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Tuple representation used by Tree SSA optimizers
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="Tree-SSA.html#Tree-SSA">Tree SSA</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Analysis and optimization of GIMPLE
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="RTL.html#RTL">RTL</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Machine-dependent low-level intermediate representation.
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="Control-Flow.html#Control-Flow">Control Flow</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Maintaining and manipulating the control flow graph.
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="Loop-Analysis-and-Representation.html#Loop-Analysis-and-Representation">Loop Analysis and Representation</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Analysis and representation of loops
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="Machine-Desc.html#Machine-Desc">Machine Desc</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">How to write machine description instruction patterns.
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="Target-Macros.html#Target-Macros">Target Macros</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">How to write the machine description C macros and functions.
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="Host-Config.html#Host-Config">Host Config</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Writing the <samp>xm-<var>machine</var>.h</samp> file.
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="Fragments.html#Fragments">Fragments</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Writing the <samp>t-<var>target</var></samp> and <samp>x-<var>host</var></samp> files.
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="Collect2.html#Collect2">Collect2</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">How <code>collect2</code> works; how it finds <code>ld</code>.
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="Header-Dirs.html#Header-Dirs">Header Dirs</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Understanding the standard header file directories.
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="Type-Information.html#Type-Information">Type Information</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">GCC&rsquo;s memory management; generating type information.
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="Plugins.html#Plugins">Plugins</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Extending the compiler with plugins.
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="LTO.html#LTO">LTO</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Using Link-Time Optimization.
</td></tr>
<tr><th colspan="3" align="left" valign="top"><pre class="menu-comment">

</pre></th></tr><tr><td align="left" valign="top">&bull; <a href="Match-and-Simplify.html#Match-and-Simplify">Match and Simplify</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">How to write expression simplification patterns for GIMPLE and GENERIC
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="Static-Analyzer.html#Static-Analyzer">Static Analyzer</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Working with the static analyzer.
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="User-Experience-Guidelines.html#User-Experience-Guidelines">User Experience Guidelines</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Guidelines for implementing diagnostics and options.
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="Funding.html#Funding">Funding</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">How to help assure funding for free software.
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="GNU-Project.html#GNU-Project">GNU Project</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">The GNU Project and GNU/Linux.
</td></tr>
<tr><th colspan="3" align="left" valign="top"><pre class="menu-comment">

</pre></th></tr><tr><td align="left" valign="top">&bull; <a href="Copying.html#Copying">Copying</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">GNU General Public License says
                    how you can copy and share GCC.
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="GNU-Free-Documentation-License.html#GNU-Free-Documentation-License">GNU Free Documentation License</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">How you can copy and share this manual.
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="Contributors.html#Contributors">Contributors</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">People who have contributed to GCC.
</td></tr>
<tr><th colspan="3" align="left" valign="top"><pre class="menu-comment">

</pre></th></tr><tr><td align="left" valign="top">&bull; <a href="Option-Index.html#Option-Index">Option Index</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Index to command line options.
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="Concept-Index.html#Concept-Index">Concept Index</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Index of concepts and symbol names.
</td></tr>
</table>


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